As is well known, a variety or products typically marketed by fast-food retail establishments are provided to consumers after having been prepared with condiments such as ketchup, mustard, mayonnaise, relish and Thousand Island dressing. In this regard, many such establishments currently utilize manual dispensing systems for such condiments which deliver a metered quantity of the condiment therefrom.
The majority of prior art condiment-dispensing systems generally comprise portable, hand-held, manually-activated dispensing devices which are used to supply a quantity of the condiment to a food product. Although such prior art dispensing systems have generally proven suitable for their intended purposes, they possess inherent deficiencies which have detracted from their overall effectiveness and use in the trade.
The foremost of these deficiencies has been the inability of the prior art dispensing devices to dispense more than one variety of condiment, in that such devices are typically suited for dispensing only one condiment at a time. Moreover, the dispensing devices currently known are generally hand-held, mechanical devices, having a storage hopper for the condiment. Due to the relatively small size of the hopper needed to permit proper handling and manipulation of the device by the user, such devices must be refilled frequently with the condiment. This need for frequent refilling decreases the operational effectiveness of the device and gives rise to a greater likelihood of condiment contamination since the device is more susceptible to having a foreign material introduced thereinto during a refilling operation.
Thus, there has existed a substantial need in the art for a reliable, relatively inexpensive apparatus for dispensing a variety of condiments through a single dispensing unit in a metered quantity and at a low flow rate, which is adapted to be connected directly to corresponding modern, sanitary bag-in-box containers for such condiments, thereby eliminating the need for frequent refillings of the dispensing system and reducing the possibility of condiment contamination. In recognition of this need, the device disclosed in application Ser. No. 07/923,136 of which the present application is a continuation-in-part was developed by the Applicant. The condiment dispensing system disclosed in Ser. No. 07/923,136 comprises a fluid driven pump having a piston which is operable to draw a quantity of condiment from a condiment reservoir into an interior cavity of the pump via an inlet check valve when it moves through an intake stroke, and dispense the quantity of condiment from the interior cavity to a dispensing apparatus via an outlet check valve when it moves through an exhaust stroke. Disposed between the piston and an inlet/exhaust port which provides the pressurized fluid needed to initiate the exhaust stroke is a rolling diaphragm which moves concurrently with the piston and prevents any condiment from entering the pressurized portion of the interior cavity. The dispensing apparatus of the system includes a plurality of valve stems which are oriented relative a plurality of fluid passages in a manner operable to provide pressurized fluid to the pump to initiate an exhaust stroke of the piston when in a first position, and allow the pressurized fluid to be vented from the pump to initiate an intake stroke of the piston when in a second position.
Though this condiment dispensing system addresses many of the deficiencies of the prior art condiment dispensing systems, this system itself has certain deficiencies which detracts from its overall utility. In this respect, it has been found that when the pump is used to dispense highly viscous condiments such as relish and Thousand Island dressing, the chunks or particles comprising or included in these condiments oftentimes are captured in the rolling diaphragm between the piston and the inner surface of the pump housing, thus causing the piston to bind up within the interior cavity and not be able to properly move through its intake and exhaust strokes. Additionally, these particles and chunks often get caught in the inlet and outlet check valves during operation of the pump, thus not allowing the valves to completely close as needed during the pump cycle. Moreover, due to the extreme differences in viscosity between condiments such as ketchup and relish, it has been found that when the valve assembly in the dispensing apparatus is designed to provide a flow rate of pressurized fluid to the pump needed to properly dispense highly viscous condiments such as relish and Thousand Island dressing therefrom, this flow rate causes less viscous condiments such as mustard and ketchup to be dispensed too rapidly from the pump, thus causing such condiments to be splattered and sprayed from the dispensing apparatus rather than being evenly and smoothly dispensed. As such, there exists a need in the art for a condiment dispensing system having the characteristics of the system disclosed in Ser. No. 07/923,136, but which is further adapted to regulate the flow of pressurized fluid to the pump depending on the type of condiment being dispensed therefrom, and is further adapted to prevent binding of the pump piston and clogging of the inlet and outlet check valves. The present invention overcomes these and other deficiencies associated with the prior art condiment dispensing systems.